多电平静止无功发生器（SVG）的研究

发布时间：2018-03-05 03:08

本文选题：无功补偿　切入点：静止无功发生器　出处：《辽宁工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着电力网络和FACTS装置的快速发展，静止无功发生器（SVG）在无功补偿方面的优势逐渐被人们所认识，其在高压输电网的无功补偿上效果尤为明显。在当今世界上高压输电网络电压等级不断提高、逐步发展智能电网的大趋势下，，静止无功发生器（SVG）成为了国内外专家学者持续关注和研究的目标。在经历了采用变压器多重化结构和传统2H桥链式结构的阶段后，如何进一步提高SVG的输出电压等级和容量，将SVG应用于现代高压输电网络，便成为了目前SVG研究领域中亟需考虑的问题。为了提高SVG的输出电压等级和容量，本文在总结SVG基本原理、多电平SVG主电路结构的基础上，通过对混合级联多电平逆变结构的分析，从输出电压能否完全PWM可控考虑，提出将直流侧电压为1E-2E的2H桥-2H桥混合级联七电平单元作为多电平链式SVG主电路的基本功率单元。这种主电路结构不需要多重化变压器，各相之间通过多个混合七电平单元相级联，能够有效提高SVG的输出电压水平和输出电压电平数。并分别采用分段载波层叠式PWM控制法和载波移相PWM控制法对单个混合七电平单元以及各相混合七电平单元之间进行控制，以进一步提升多电平链式SVG的性能。通过对载波移相PWM控制法进行改进，又可以将链式SVG的电容电压不平衡控制在一定范围之内。最后本文通过MATLAB软件中的SIMULINK对此多电平链式SVG系统进行了仿真，并与相对应的传统2H桥链式SVG进行了比较。仿真结果表明，以混合七电平单元为基本功率单元的多电平链式SVG性能较好，具有一定的实用意义。
[Abstract]:With the rapid development of power network and FACTS devices, the advantages of static Var Generator (SVG) in reactive power compensation have been gradually recognized. Its effect on reactive power compensation of HV transmission network is especially obvious. In the world, the voltage level of HV transmission network is increasing constantly, and the trend of developing smart grid step by step, The static Var Generator (SVG) has become the object of continuous attention and research by experts and scholars at home and abroad. After the stage of adopting the transformer multiplex structure and the traditional 2H bridge chain structure, how to further improve the output voltage level and capacity of SVG. The application of SVG in modern HV transmission network has become an urgent problem in the field of SVG research. In order to improve the output voltage and capacity of SVG, on the basis of summarizing the basic principle of SVG and the structure of multilevel SVG main circuit, this paper analyzes the hybrid cascade multilevel inverter structure and considers whether the output voltage can be completely controlled by PWM. In this paper, the 2H bridge -2H bridge hybrid cascaded seven-level cell with DC voltage of 1E-2E is used as the basic power unit of the multilevel chain SVG main circuit. Each phase is cascaded through a plurality of mixed seven-level cells, The output voltage level and the output voltage level of SVG can be improved effectively, and the single mixed seven-level unit and each phase mixed seven-level unit are controlled by the piecewise carrier stacked PWM control method and the carrier phase-shifted PWM control method, respectively. In order to further improve the performance of multilevel chained SVG, the carrier phase-shifted PWM control method is improved. The capacitor voltage imbalance of chain SVG can also be controlled within a certain range. Finally, the multilevel chain SVG system is simulated by SIMULINK in MATLAB software. The simulation results show that the hybrid seven-level unit is the basic power unit of the multi-level chain SVG performance is better, has certain practical significance.
【学位授予单位】：辽宁工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM761.12

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